The present invention relates generally to water treatment systems and, more specifically, to a Legionella bacteria dispersant and eradicator system for use in a water treatment system.
Legionella is the named genus of gram-negative, rod shaped, aerobic bacteria that is very common to aquatic warm water environments. Legionellosis is any illness caused by exposure to Legionella that occurs when a person inhales aerosols or other microscopic droplets of water containing Legionella microorganisms, and is commonly referred to as the potentially fatal Legionnaires Disease. In typical city water supply systems, the end devices for water delivery systems capable of dispersing the Legionella bacteria include faucets and showerheads.
The conditions that promote growth of this bacteria in water systems include stagnant water, a pH generally between 5 and 8, water temperatures between 68xc2x0 and 122xc2x0 F., and the sediment, scale, deposits and biofilms in the pipe systems. It is known that conventional hot water systems can provide most, if not all, of the above stated conditions necessary to potentially promote growth of the Legionella bacteria.
Conventional methods for controlling growth and dispersion of the Legionella bacteria include; A) the Heat-and-Flush Method; B) Chlorination; C) Ultraviolet radiation; D) Ozonation; and E) and Copper-Silver Ionization. The Heat-and-Flush Method involves superheating the water system and flushing all outlets for several minutes. The drawback to this method is that the Legionella bacteria may come back since the scale and biofilms in the plumbing where the bacteria lives are not destroyed, and/or the incoming water recontaminates the water with legionella bacteria. When the Chlorination method is used to provide temporary disinfection, chlorine is added to the water system at free levels much higher than normal for drinking water and is flushed throughout the system. For continuous disinfection, chlorine is pumped into water systems at a drinkable concentration of 1-2 mg/L of free chlorine throughout the domestic water system. However, chlorine is a very strong oxidizer and will quickly create corrosion that destroys the plumbing system. In addition, when chlorine mixes with organics, it can produce compounds thought to cause cancer, thereby requiring the system to be constantly monitored to ensure proper dosage.
As noted, another conventional method requires installation of an ultraviolet sterilizer unit on a water line to kill the legionella bacteria as the water flows through the unit. Unfortunately, the use of an ultraviolet sterilizer unit is not effective if the water system is already contaminated since the downstream bacteria cannot pass through the sterilizer unit. As an alternative, the Ozonation method involves dissolving ozone molecules into the water system to achieve a dose of about 1-2 mg/L of ozone. This dosage of ozone is effective to kill the bacteria. One drawback, however, is that ozone systems are extremely corrosive because ozone is a very strong oxidizer. Further, ozone generators are known to be temperamental and expensive.
The Copper-Silver Ionization method used for killing Legionella bacteria is operable to apply an alloy of copper and silver that is located in the stream with the water supply. The free copper and silver ions that are electrochemically released are effective in killing the bacteria. However, the electrochemical release of these ions could produce over concentrations in certain areas. Furthermore, over time, scaling deposits will form on the copper-silver alloy and will hinder ion release. In addition, this technology has certain water chemistry parameters, and silver is a registered pesticide with the EPA which requires strict monitoring constantly.
It is therefore desirable to provide an improved method or system for eliminating growth and dispersion of the Legionella bacteria in water systems. The system as detailed below and in the attached drawing entails a novel method of using certain available systems and components to eradicate conditions for Legionella and/or the bacteria itself.
Accordingly, it is the object of the present invention to provide a Legionella bacteria dispersant and eradicator system for use in a water treatment system.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.